title: Sublinear binocular integration preserves orientation selectivity in mouse visual cortex.
abstract: Inputs from the two eyes are first combined in simple cells in the primary visual cortex. Consequently, visual cortical neurons need to have the flexibility to encode visual features under both monocular and binocular situations. Here we show that binocular orientation selectivity of mouse simple cells is nearly identical to monocular orientation selectivity in both anaesthetized and awake conditions. In vivo whole-cell recordings reveal that the binocular integration of membrane potential responses is sublinear. The sublinear integration keeps binocularly evoked depolarizations below threshold at non-preferred orientations, thus preserving orientation selectivity. Computational simulations based on measured synaptic conductances indicate that inhibition promotes sublinear binocular integration, which are further confirmed by experiments using genetic and pharmacological manipulations. Our findings therefore reveal a cellular mechanism for how visual system can switch effortlessly between monocular and binocular conditions. The same mechanism may apply to other sensory systems that also integrate multiple channels of inputs.
authors.affiliation: Department of Neurobiology, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Zhao
authors.forename: Mingna
authors.initials: M
authors.lastname: Liu
authors.forename: Jianhua
authors.initials: J
authors.lastname: Cang
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D003337:Corpus Callosum / Q000502:physiology; D051379:Mice; D009949:Orientation / Q000502:physiology*; D010775:Photic Stimulation; D013569:Synapses / Q000502:physiology; D015348:Vision, Binocular / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*